INDEX 



979 



Testosterone, 22, 23, 26, 41 



examples of stimulation, 27 



in testicular descent, 12 

 Testudinata, xix 



Testudo graeca, developing egg of, 167 

 Tetrad, 137 

 Tetrapoda, pectoral girdle of, 689 



pelvic girdle of, diagrammatic, 689 

 TeWinkle, L. E., 914 

 Thamnophis radix, garter snake, xix 

 Theca externa, of mature Graafian follicle, 



71, 74 

 Theca interna, of mature Graafian follicle, 



71, lA 

 Thecodont teeth, 605 



development of, 610 

 Theelin, 85 

 Theria, xx 

 Thickened keel method, of neuralization, 



465 

 Thigmotaxis, during cleavage, 328 

 Thimann, K. V., 12 



Thin roof plate, of developing brain, 822 

 Thoracic duct, 764 



Thoracicolumbar autonomic system, 836 

 Throat sweetbread (thymus), 880 

 Thymocytes, 880 



Thymus gland, 619, 726, 878, 880 

 Thyng, F. W., 625 

 Thyroglossal duct, 878 

 Thyroid gland, 619, 877 



effect of on development of chick, 884 



effect of on development of mammal, 

 885 



embryonic origin of, 878 



histogenesis of, 879 



in vertebrate embryology, general con- 

 clusions, 886 



influence of on development of fishes, 

 885 



influence on anuran metamorphosis, 883 



isthmus of, 877 



of human embryo, 878 

 Thyroid-gland diverticulum, 601 

 Thyroxine, 877 

 Tichomiroff, 217 

 Tissue, definition of, 517 



four fundamental, of the embryo, 519, 

 520 



interstitial, 15, 17 



and male sex hormone production, 23, 

 24 

 Toad, amplexus in, 185 

 Toad test, for pregnancy, 927 

 Tongue, bird, copula of. 604 



development of, 603 



innervation of, 717 



mammalian copula of, 605 



Tongue — (Continued) 



of frog, 603 



of shark, 603 



origin of musculature of, 717 



protrusile, 603 



true, flexible, 603 

 Tonsils, 726 

 Tooth, development of in mammals, 608 



egg, in chick, 608 



epithelial sheath of, 613 

 Torpedo ocellafa, germ disc of, 318 

 Tortoise shell, of commerce, 569 

 Totipotency, definition of, 376 



in teleost blastoderm, 385 

 Totipotential condition, of Roux, 377 

 Townsend, G., 228 



Toxopneiistes lividus, fertilization mem- 

 brane in, 214 



gametic fusion in, 214 

 Toxopneiistes variegatus, fertilization cone 



in, 241, 263 

 Trabeculae, of spongy bone, 662 

 Trabeculae carnae of heart, 757 

 Trabecular area, of primitive skull, 671 

 Trachea, cellular composition of, 649 

 Transplantation experiments, in Triton, 381 

 Transverse division, primitive, formation 



of, 859 

 Trapezius musculature, in human, 718 

 Trichosurus, derivation of eye muscles in, 



716 

 Trigeminal nerve (cranial n. v.), 717, 828 

 Triton, European newt, gastrula, 355 



polyspermy in, 270 

 Triton cristatus, xvii 



transplantation experiments in, 381 

 Triton taeniatus, transplantation experi- 

 ments in, 381 

 Triturus viridescens, xvii 



cleavage of partially constricted egg of, 

 332 



first cleavage plane in, 287 



reproductive activity and temperature in, 

 46 

 Truncus arteriosus, 759 

 Trunk, muscles of, development of, 705, 



710 

 Trunk or tail organizer, ability of, 401, 512 

 Trutta irideus, xvii 

 Tuatera, xviii 



Tube, uterine (Fallopian), 64 

 Tuberculum impar, of developing bird 

 tongue, 603 



of mammalian tongue, 605 

 Tubulated areas, regional modifications of, 

 457 



